INA 200mm f4.5 - strange lens

This is a strange lens I got, that won't focus to infinity. It has a removable M42 mount with a "P" marking. I assume that means it's for Pentax M42 not something other mount with threads of the same size.

Vinson is the manufacturer, sometimes as Ina Vinson or Vinson Ina (something like that). They're a Japaneses company in the 60's and 70's that made re-bagged lenses usually from Sankyō Kōki Komura. I *think* that's what you've got.